How to say "familial" in Japanese

• 家族性かぞくせい
  no-adjectiveCovers the technical sense of 'familial' — a trait, disease, or characteristic that runs in families. Common in medical, genetic, and scientific writing, as in describing familial conditions or patterns of inheritance.
• 家庭的かていてき
  na-adjectiveMatches the gloss 'familial' but really means 'family-oriented' or 'homely' — describing a warm, homey atmosphere or a person devoted to their family. For the clinical 'familial' sense it is seldom the word you want.
  あの旅館りょかんは家庭的かていてきだ。↗

  The hotel has a homey atmosphere.

Use 家族性 for the technical, medical or genetic sense of 'familial' (running in families); 家庭的 covers the everyday 'family-oriented, homely' sense and is rarely the word for anything else.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 家族性かぞくせいfamilial
• 家庭的かていてきfamily-oriented